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-rw-r--r--src/expr.c135
1 files changed, 84 insertions, 51 deletions
diff --git a/src/expr.c b/src/expr.c
index b4461cf5c..de729ea62 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -5831,6 +5831,67 @@ static void exprCodeBetween(
}
/*
+** Compute the two operands of a binary operator.
+**
+** If either operand contains a subquery, then the code strives to
+** compute the operand containing the subquery second. If the other
+** operand evalutes to NULL, then a jump is made. The address of the
+** IsNull operand that does this jump is returned. The caller can use
+** this to optimize the computation so as to avoid doing the potentially
+** expensive subquery.
+**
+** If no optimization opportunities exist, return 0.
+*/
+static int exprComputeOperands(
+ Parse *pParse, /* Parsing context */
+ Expr *pExpr, /* The comparison expression */
+ int *pR1, /* OUT: Register holding the left operand */
+ int *pR2, /* OUT: Register holding the right operand */
+ int *pFree1, /* OUT: Temp register to free if not zero */
+ int *pFree2 /* OUT: Another temp register to free if not zero */
+){
+ int addrIsNull;
+ int r1, r2;
+ Vdbe *v = pParse->pVdbe;
+
+ assert( v!=0 );
+ /*
+ ** If the left operand contains a (possibly expensive) subquery and the
+ ** right operand does not and the right operation might be NULL,
+ ** then compute the right operand first and do an IsNull jump if the
+ ** right operand evalutes to NULL.
+ */
+ if( ExprHasProperty(pExpr->pLeft, EP_Subquery)
+ && !ExprHasProperty(pExpr->pRight, EP_Subquery)
+ && sqlite3ExprCanBeNull(pExpr->pRight)
+ ){
+ r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pFree2);
+ addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r2); VdbeCoverage(v);
+ }else{
+ addrIsNull = 0;
+ }
+ r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, pFree1);
+ if( addrIsNull==0 ){
+ /*
+ ** If the right operand contains a subquery and the left operand does not
+ ** and the left operand might be NULL, then check the left operand do
+ ** an IsNull check on the left operand before computing the right
+ ** operand.
+ */
+ if( ExprHasProperty(pExpr->pRight, EP_Subquery)
+ && sqlite3ExprCanBeNull(pExpr->pLeft)
+ ){
+ addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r1); VdbeCoverage(v);
+ }
+ r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pFree2);
+ }
+ *pR1 = r1;
+ *pR2 = r2;
+ return addrIsNull;
+}
+
+
+/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
** continues straight thru if the expression is false.
@@ -6076,75 +6137,47 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
break;
}
case TK_IS:
- case TK_ISNOT:
+ case TK_ISNOT: {
testcase( pExpr->op==TK_IS );
testcase( pExpr->op==TK_ISNOT );
+ if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
- jumpIfNull = SQLITE_NULLEQ;
- /* no break */ deliberate_fall_through
+ r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+ r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
+ codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
+ r1, r2, dest, SQLITE_NULLEQ,
+ ExprHasProperty(pExpr,EP_Commuted));
+ testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
+ testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
+ break;
+ }
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
- int r2Done = 0;
- int addrBypass = 0;
+ int addrIsNull;
if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
- testcase( jumpIfNull==0 );
- /*
- ** If the left operand is a (possibly expensive) subquery and the
- ** right operand is not and the right operation might be NULL and
- ** the operator is not IS or IS NOT, then compute the right operand
- ** first and skip the computation of the left operand if the right
- ** operand is NULL.
- */
- if( jumpIfNull!=SQLITE_NULLEQ
- && ExprHasProperty(pExpr->pLeft, EP_Subquery)
- && !ExprHasProperty(pExpr->pRight, EP_Subquery)
- && sqlite3ExprCanBeNull(pExpr->pRight)
- ){
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
- addrBypass = sqlite3VdbeAddOp2(v, OP_IsNull, r2, dest);
- VdbeCoverageIf(v, jumpIfNull==SQLITE_JUMPIFNULL);
- VdbeCoverageIf(v, jumpIfNull!=SQLITE_JUMPIFNULL);
- if( jumpIfNull==SQLITE_JUMPIFNULL ) addrBypass = 0;
- r2Done = 1;
- }
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
- if( !r2Done ){
- /*
- ** If the right operand is a subquery and the left operand is not
- ** and the left operand might be NULL and the comparison operator
- ** is not IS or IS NOT, then check the left operand to see if it is
- ** NULL and skip the computation of the right operand if it is.
- */
- if( jumpIfNull!=SQLITE_NULLEQ
- && ExprHasProperty(pExpr->pRight, EP_Subquery)
- && sqlite3ExprCanBeNull(pExpr->pLeft)
- ){
- addrBypass = sqlite3VdbeAddOp2(v, OP_IsNull, r1, dest);
- VdbeCoverageIf(v, jumpIfNull==SQLITE_JUMPIFNULL);
- VdbeCoverageIf(v, jumpIfNull!=SQLITE_JUMPIFNULL);
- if( jumpIfNull==SQLITE_JUMPIFNULL ) addrBypass = 0;
- }
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
- }
+ addrIsNull = exprComputeOperands(pParse, pExpr,
+ &r1, &r2, &regFree1, &regFree2);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
- assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
- VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
- VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
- assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
- VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
- VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
+ assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
+ assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
testcase( regFree1==0 );
testcase( regFree2==0 );
- if( addrBypass ) sqlite3VdbeJumpHere(v, addrBypass);
+ if( addrIsNull ){
+ if( jumpIfNull ){
+ sqlite3VdbeChangeP2(v, addrIsNull, dest);
+ }else{
+ sqlite3VdbeJumpHere(v, addrIsNull);
+ }
+ }
break;
}
case TK_ISNULL:
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-15 18:30:44 +0000